README.md in grumlin-0.21.1 vs README.md in grumlin-0.22.0

@@ -62,19 +62,24 @@
 explicitly specify the provider you use.
 
 #### Provider features
 
 Every provider is described by a set of features. In the future `Grumlin` may decide to disable or enable 
-some parts of it's functionality to comply provider's supported features. Currently there is no difference
-in behaviour when working with different providers.
+some parts of it's functionality to comply provider's supported features.
 
 To check current providers supported features use
 
 ```ruby
 Grumlin.features
 ```
 
+Current differences between providers:
+
+| Feature      | TinkerGraph                                                                                                                                               |AWS Neptune|
+|--------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------|-----------|
+| Transactions | Transaction semantic is ignoroed, data is always writen, `tx.rollback` does nothing, an info is printed every time transactions are used with TinkerGraph |Full support
+
 ### Traversing graphs
 
 **Warning**: Not all steps and expressions defined in the reference documentation are supported.
 
 #### Sugar
@@ -238,25 +243,32 @@
 - `:single` - `next`
 - `:none` - `iterate`
 - `:traversal` - do not execute the query and return the traversal as is
 
 `Grumlin::Repository` also provides a set of generic CRUD operations:
-- `add_vertex(label, id = nil, **properties)`
-- `add_edge(label, id = nil, from:, to:, **properties)`
-- `drop_vertex(id)`
-- `drop_edge(id = nil, from: nil, to: nil, label: nil)`
+- `add_vertex(label, id = nil, start: g, **properties)`
+- `add_edge(label, id = nil, from:, to:, start: g, **properties)`
+- `drop_vertex(id, start: g)`
+- `drop_edge(id = nil, from: nil, to: nil, label: nil, start: g)`
 
 and a few methods that emulate upserts:
-- `upsert_vertex(label, id, create_properties: {}, update_properties: {}, on_failure: :retry, **params)` 
-- `upsert_edge(label, from:, to:, create_properties: {}, update_properties: {}, on_failure: :retry, **params)`
-- `upsert_edges(edges, batch_size: 100, on_failure: :retry, **params)`
-- `upsert_vertices(edges, batch_size: 100, on_failure: :retry, **params)`
+- `upsert_vertex(label, id, create_properties: {}, update_properties: {}, on_failure: :retry, start: g, **params)` 
+- `upsert_edge(label, from:, to:, create_properties: {}, update_properties: {}, on_failure: :retry, start: g, **params)`
+- `upsert_edges(edges, batch_size: 100, on_failure: :retry, start: g, **params)`
+- `upsert_vertices(edges, batch_size: 100, on_failure: :retry, start: g, **params)`
 
 All of them support 3 different modes for error handling: `:retry`, `:ignore` and `:raise`. Retry mode is implemented
 with [retryable](https://github.com/nfedyashev/retryable). **params will be merged to the default config for upserts 
 and passed to `Retryable.retryable`. In case if you want to modify retryable behaviour you are to do so.
 
+If you want to use these methods inside a transaction simply pass your `gtx` as `start` parameter:
+```ruby
+g.tx do |gtx|
+  add_vertex(:vertex, start: gtx)
+end
+```
+
 If you don't want to define you own repository, simply use
 
 `Grumlin::Repository.new` returns an instance of an anonymous class extending `Grumlin::Repository`. 
 
 **Usage**
@@ -279,9 +291,27 @@
 
 `query` also provides a helper for profiling requests:
 `MyRepository.new.triangles_with_color(:red, query_params: { profile: true })`
 
 method will return profiling data of the results.
+
+#### Transactions
+
+Since 0.22.0 `Grumlin` supports transactions when working with providers that supports them:
+```ruby
+# Using Transaction directly
+tx = g.tx
+gtx = tx.begin
+gtx.addV(:vertex).iterate
+tx.commit # or tx.rollback
+
+# Using with a block
+g.tx do |gtx|
+  gtx.addV(:vertex).iterate
+  # raise Grumlin::Rollback to manually rollback
+  # any other exception will also rollback the transaction and will be reraised 
+end # commits automatically
+```
 
 #### IRB
 
 An example of how to start an IRB session with support for executing gremlin queries: